Conventionally, various proposals have been made for an erasable heat-sensitive recording material having a heat-sensitive recording layer whose transparency depends on temperature. For example, the fourth non-impact printing technology symposium theses and Japanese unexamined patent publication Hei 2-258287 (1990) describe a material having an erasable heat-sensitive recording layer, which is formed on a support and has an organic substance of low molecular weight, dispersed in a binding resin, to which writing and erasing are carried out thermally using a thermal head.
A conventional erasable heat-sensitive recording material, however, requires a high printing energy, and the printing characteristics of a thermal head which emits energy corresponding to the heat-sensitive recording layer are unsatisfactory, resulting in a very short thermal head life, requiring a long pulse input for printing or entailing a much-reduced printing speed. Attempts have been made to improve printing characteristics by reducing the film thickness of the heat-sensitive recording layer, increasing the amount of organic substance of low molecular weight dispersed in the binder resin. In this case again, the optical contrast of the image and background portion and the repeatability decline, and an image of high resolution cannot be obtained, because of the high thermal diffusion caused by the image input using a thermal head.